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[committed][PATCH] Handle unsorted section header table
Hi,
Committed as attached.
Thanks,
- Tom
Handle unsorted section header table
Consider a hello world, with .gdb_index added by the gold linker. When
running dwz, we run into this error:
...
$ gcc hello.c -g -fuse-ld=gold -Wl,--gdb-index
$ dwz a.out
dwz: Section offsets in a.out not monotonically increasing
...
Inspecting the section offsets around .gdb_index:
...
$ readelf -S a.out | grep '[[]' | egrep -C1 'Offset|\.gdb_index'
[Nr] Name Type Address Offset
[ 0] NULL 0000000000000000 00000000
--
[31] .debug_str PROGBITS 0000000000000000 00001b2f
[32] .gdb_index PROGBITS 0000000000000000 000034b0
[33] .debug_ranges PROGBITS 0000000000000000 000021f0
...
indeed shows that the offsets are not monotonically increasing.
Handle unsorted section header table in write_dso by rewriting the file
offfset alignment updating loops to loop in file offset order.
2019-03-23 Tom de Vries <tdevries@suse.de>
PR dwz/24249
* Makefile (TEST_EXECS): Add hello-gold-gdb-index.
(hello-gold-gdb-index): New target.
* dwz.c (write_dso): Handle aligning file offsets of unordered section
header table.
* testsuite/dwz.tests/dwz-tests.exp: Require hello-gold-gdb-index for
gold-gdb-index.sh.
* testsuite/dwz.tests/gold-gdb-index.sh: New test.
---
Makefile | 6 +++++-
dwz.c | 31 +++++++++++++------------------
testsuite/dwz.tests/dwz-tests.exp | 3 +++
testsuite/dwz.tests/gold-gdb-index.sh | 7 +++++++
4 files changed, 28 insertions(+), 19 deletions(-)
diff --git a/Makefile b/Makefile
index 2d9ba4e..1193283 100644
--- a/Makefile
+++ b/Makefile
@@ -24,7 +24,7 @@ PWD:=$(shell pwd -P)
TEST_SRC = $(srcdir)/testsuite/dwz.tests
TEST_EXECS = hello dw2-restrict py-section-script dwz-for-test min two-typedef \
- dw2-skip-prologue start implptr-64bit-d2o4a8r8t0
+ dw2-skip-prologue start implptr-64bit-d2o4a8r8t0 hello-gold-gdb-index
hello:
$(CC) $(TEST_SRC)/hello.c -o $@ -g
@@ -62,6 +62,10 @@ implptr-64bit-d2o4a8r8t0:
$(CC) $(TEST_SRC)/implptr-64bit-d2o4a8r8t0.S $(TEST_SRC)/main.c -o $@ \
-g || touch $@
+hello-gold-gdb-index:
+ $(CC) $(TEST_SRC)/hello.c -g -fuse-ld=gold -Wl,--gdb-index -o $@ \
+ || touch $@
+
# On some systems we need to set and export DEJAGNU to suppress
# WARNING: Couldn't find the global config file.
DEJAGNU ?= /dev/null
diff --git a/dwz.c b/dwz.c
index 3389ff0..a73fe38 100644
--- a/dwz.c
+++ b/dwz.c
@@ -10667,9 +10667,12 @@ write_dso (DSO *dso, const char *file, struct stat *st)
>= min_shoff aren't non-ALLOC. */
GElf_Off last_shoff = 0;
int k = -1;
- bool shdr_placed = false;
- for (j = 1; j < dso->ehdr.e_shnum; ++j)
- if (dso->shdr[j].sh_offset < min_shoff && !last_shoff)
+ int l;
+ for (l = 1, j = sorted_section_numbers[l]; l <= dso->ehdr.e_shnum;
+ ++l, j = sorted_section_numbers[l])
+ if (j == dso->ehdr.e_shnum)
+ continue;
+ else if (dso->shdr[j].sh_offset < min_shoff && !last_shoff)
continue;
else if ((dso->shdr[j].sh_flags & SHF_ALLOC) != 0)
{
@@ -10677,35 +10680,27 @@ write_dso (DSO *dso, const char *file, struct stat *st)
"ones", dso->filename);
return 1;
}
- else if (dso->shdr[j].sh_offset < last_shoff)
- {
- error (0, 0, "Section offsets in %s not monotonically "
- "increasing", dso->filename);
- return 1;
- }
else
{
+ assert (dso->shdr[j].sh_offset >= last_shoff);
+
if (k == -1)
- k = j;
+ k = l;
last_shoff = dso->shdr[j].sh_offset + dso->shdr[j].sh_size;
}
last_shoff = min_shoff;
- for (j = k; j <= dso->ehdr.e_shnum; ++j)
+ for (l = k, j = sorted_section_numbers[l]; l <= dso->ehdr.e_shnum;
+ ++l, j = sorted_section_numbers[l])
{
- if (!shdr_placed
- && ehdr.e_shoff >= min_shoff
- && (j == dso->ehdr.e_shnum
- || ehdr.e_shoff < dso->shdr[j].sh_offset))
+ if (j == dso->ehdr.e_shnum)
{
if (ehdr.e_ident[EI_CLASS] == ELFCLASS64)
ehdr.e_shoff = (last_shoff + 7) & -8;
else
ehdr.e_shoff = (last_shoff + 3) & -4;
last_shoff = ehdr.e_shoff + ehdr.e_shnum * ehdr.e_shentsize;
- shdr_placed = true;
+ continue;
}
- if (j == dso->ehdr.e_shnum)
- break;
dso->shdr[j].sh_offset = last_shoff;
if (dso->shdr[j].sh_addralign > 1)
dso->shdr[j].sh_offset
diff --git a/testsuite/dwz.tests/dwz-tests.exp b/testsuite/dwz.tests/dwz-tests.exp
index c1f913a..108b167 100644
--- a/testsuite/dwz.tests/dwz-tests.exp
+++ b/testsuite/dwz.tests/dwz-tests.exp
@@ -42,6 +42,9 @@ foreach test $tests {
if { $basename == "pr24170.sh" } {
lappend required_execs "implptr-64bit-d2o4a8r8t0"
}
+ if { $basename == "gold-gdb-index.sh" } {
+ lappend required_execs "hello-gold-gdb-index"
+ }
if { ![istarget x86_64-*-*] } {
if { $basename == "pr24468.sh" } {
unsupported "$test"
diff --git a/testsuite/dwz.tests/gold-gdb-index.sh b/testsuite/dwz.tests/gold-gdb-index.sh
new file mode 100644
index 0000000..eb2a164
--- /dev/null
+++ b/testsuite/dwz.tests/gold-gdb-index.sh
@@ -0,0 +1,7 @@
+cp ../hello-gold-gdb-index 1
+
+dwz 1
+
+smaller-than.sh 1 ../hello-gold-gdb-index
+
+rm -f 1